Substituted methylene diphosphonic acids and salts and esters thereof



Patented .ian. 17, 1967 ACIDS AND SALTS AND EEQTERS THEREQF Steven J. Fitch, Creve Coeur, and Rio/ad R. llrani, Florissant, M0,, assignors to Monsanto Company, a corporation of Delaware No Drawing. Filed Apr. 9, 1963, Ser. No. 271,607

13 Claims. Cl. lath-50th) This invention relates to organic compounds of phosphorus, compositions containing said compounds, and uses thereof.

An object of this invention is to provide new and useful organic compounds of phosphorus containing a PC-P group in their molecules.

A further object of this invention is to provide new and useful organic compounds of phosphorus containing a I335 PCP group in their molecules with the C group being a hydrophobic and/ or lipophilic groups.

A further object of this invention is to provide new and useful organophosphonic acids, as well as their salts and esters.

A more specific object of this invention is to provide new and useful organo-methylene diphosphonic acids or the salts thereof which exhibit, among other things, combined surfactancy, sequestering and deflocculating properties.

A more specific object of this invention is to provide new and useful organo-met-hylene diphosphonate esters which exhibit, among other things, the unique ability of solubilizing water in water immiscible solvents.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonic acids or the salts thereof.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonic acids or the salts thereof which are suitable for use in aqueous systems.

Another object of this invention is to provide detergent compositions containing organo-methylene diphosphonate esters.

A still further object of this invention is to provide detergent compositions containing organo-methylene diphosphonate esters which are suitable for use as dry-cleaning detergents in organic solvents.

A still further object of this invention is to provide gasoline additive compositions containing organo-methylene diphosphonate esters.

Other objects of this invention will appear from the description hereinafter.

This invention is directed to new and useful organomethylene diphosphonic acid compounds, as well as the salts and esters thereof, said compounds having the gen eral formula.

( X0 0 R 0 OX \H l ll/ P-G-P wherein: R is selected from the class consisting of aliphatic hydrocarbyl, alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and carbon containing heterocyclic groups and X is selected fro-m the class con sisting of cations selected from the group consisting of hydrogen ions, alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions and amine ions, and aliphatic hydrocarbyl, aryl, alkaryl and aralkyl groups of from 1 to 30 carbon atoms. When the symbols R and X represent groups containing carbon chains, such as aliphatic hydrocarbyl groups, or groups containing alkyl moieties, i.e., aralkyl groups, such carbon chains may be of a straight chain structure or branch chain structure. For the symbols R and X when the represent aliphatic hydrocarbyl groups, such groups may be saturated or unsaturated. For most end use'applications the compound of the instant invention should preferably contain not more than 25 carbon atoms associated with R and X (when X represents ester groups, and there are few, if any, end uses, in which'the foregoing groups contain more than a total of 50 carbon atoms.

These compounds can be characterized quite generally as having a PC-P linkage in their molecules and are generically described in this specification by the general terms organo-methylene diphosphonic acids, the salts of organo-rnethylene diphosphonic acids, and the esters of organo-methylene diphosphonic acids.

The compounds of the invention can be prepared by various methods with the following methods presented as being representative of their preparation.

The ester of the organo-methylene diphosphonic acids can be prepared by first forming a mctallo-derivative of a methylene diphosphonate ester and reacting this metallO ester derivative with an organo-halide to produce the desired organo-methylene diphosphonate ester. The reaction of the metallo-ester derivative with the organohalide is believed represented by the following equation:

wherein Rrepresents the same groups as in the foregoing general Formula 1.

In general, metallo-derivatives of the tetraester methylene diphosphonate can be prepared in several ways. When preparing the Group IA (alkali metals) ester derivatives and particularly the sodioand potassioester derivatives it is usually only necessary to react the alkali metal directly with the ester. The reaction is often exothermic so that, in most cases, it maybe necessary to bring the reactants together while cooling, to dilute the mixture with an inert solvent such as xylene, benzene, toluene, ether, dioxane, hexane and the like, or to add the sodium or potassium slowly to the esters in the inert solvent. In some cases it may be necessary to employ all of the immediately foregoing procedures. It is usually advantageous to heat the reaction mixture for the last few minutes of the reaction, however, in order to facilitate the reaction, The Group lI-A (alkaline earth metals) and in particular the calcium and magnesium metals can, in most cases, be reacted with the tetra-ester of the methylene diphosphonate in the presence of pyridine with the higher esters requiring in most cases moderate heating for completion of the reaction. In some cases it is also possible to prepare the Group l-B metal derivatives, and in particular the silver-ester derivative and cuprous-ester derivative; the Group II-B metal derivatives, and in particular the zinc-ester derivatives; and Group IV-A metal derivatives, and in particular the leadand tin-ester derivatives by methods which are similar to the foregoing methods. Because of the relative inexpensiveness and the ready availability of sodium and potassium and because of their rather straight forward reaction with the ester it is gen erally advantageous to form the sodioand po-tassio-ester derivatives and, therefore, sodium and potassium are the preferred metals for use in forming these ester derivatives.

In general, the reaction of the metallo-ester derivatives with an organo halide, i.e., Reaction 2, is relatively straight forward. Oftentimes, however, it may be necessary to use temperatures above room temperature, i.e., about 25 C., in order to facilitate the reaction with temperatures of between about 70 C. to about 180 C. usually being sufficient. In most cases, depending on the temperature used, a definite precipitate forms, i.e., metal-halide, after a period of time of between about 10 minutes and about 4 hours. The precipitate may be removed by several well known methods, such as, filtration, centrifugation and decantation, or by dissolution with water and phase separation, and, if desired, the filtrate can thereafter be distilled to improve the purity of the organo-methylene diphosphonate ester.

It may be necessary, however, when using organo halides containing substituent groups, such as, hydroxyl, carboxylic acid, and halides, to protect these groups during the reaction. Usually the carboxylic acid groups can be protected by the well known method of esterification prior to the reaction and hydrolysis of the ester subsequent to the reaction. Also the hydroxyl group can usually be protected by the well known method of ether formation using such materials as dihydropyrane, benzyl chloride, tritychloride and the like to form the ethers followed by removal of the protective groups by such methods as hydrolysis with dilute mineral acids, catalytic hydrogenation, or chemical reduction. In addition, by using well known methods the halide group of polyhalide compounds can usually be protected by conversion into an ether group, a common reactant being sodium alkoxide, and the ether group subsequently cleaved with a hydrogen halide to remove the protective ether groups.

The organo-methylene diphosphonic acid can be prepared by the hydrolysis of the corresponding esters with a concentrated mineral acid. Generally, by refluxing the ester and a concentrated mineral acid, such as HCl or HBr, at reflux temperatures for a period of usually about five hours is all that is necessary for the hydrolysis.

The salts of the organo-methylene diphosphonic acids can be prepared by neutralization of the acids with a stoichiometric amount of a base or a salt of a volatile acid that contains essentially the desired cation. Bases or salts of volatile acids such as those containing an alkali metal, alkaline earth metal, aluminum, ammonia and amines are especially suited. For example, to make a sodium salt, one of organo-methylene diphosphonic acids can he neutralized with a stoichiometric amount of a base containing the sodium cation, such as NaOH, Na CO and the like. It should be noted that organo-methylene diphosphonic acid titrates using a pH meter as a tribasic acid, however, the tetra salts can be prepared by neutralization of the acids with a stoichiometric amount of a base and evaporating to dryness. In addition, it has been found if the acids are titrated using a pH meter in the presence of a 10% NaCl solution they will titrate as tetra-basic acids.

The following examples are presented to illustrate the invention, with parts by Weight being used in the examples unless otherwise indicated.

Example 1 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 288 grams tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 65 C. After all of the potassium is used up about 179 grams of n-heptyl bromide is added dropwise to the reaction mixture. To ensure a satisfactory degree of reaction the mixture is heated between about 100 C. and 140 C. for about 10 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester as a colorless liquid. Analysis of the P NMR spectra of the ester indicates tetraethyl octylidene diphosphonate, C7H15CH[PO(OC2H5)2]2 with a small amount of impurity of tetraethyl methylene diphosphonate. Elemental analysis yields the following results:

Calculated: C, 49.80%; H, 9.39%. 46.82%; H, 9.51%.

Found: C,

4 Example 2 The ester prepared according to Example 1 is hydrolyzed to the acid by refluxing about 386 grams with about 600 ml. concentrated HCl for about 5 hours. Evaporation to dryness yields the acid, octylidene diphosphonic acid, C H CH[PO(OH) The equivalent weight of this product, by tritration, is found to be about 98.0 which compares favorably with the calculated value of about 91.3. Elemental analysis yields the following results:

Calculated: C, 35.00%; H, 7.29%. Found: C, 33.17%; H, 6.89%.

Example 3 Trisodium octylidene diphosphonate C H CH[PO(ONa [PO(ONa) (OH)] is prepared by dissolving about 274 grams of free acid obtained as in Example 2 in about 1.2 liters of 10% NaOH solution and evaporating the aqueous solution to dryness at about 140 C. with the anhydrous form of the salt being formed.

Example 4 Into a suitable reaction vessel about 39.1 grams potassium metal is added slowly to about 288 grams tetraethyl methylene diphosphonate in about 2.5 liters of Xylene. The temperature of the reaction vessel is maintained at about C. After all of the potassium is used up about 247 grams of n-dodecylbromide is added dropwise to the reaction mixture. To ensure a satisfactory degree of reaction the mixture is heated at about C. for about 4 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester as a colorless liquid. Analysis of the P NMR spectra of the ester indicated tetraethyl tridecylidene diphosphonate,

Elemental analysis of this product yields the following results:

Calculated: C, 55.3%; H, 10.2%; P, 13.6%. C, 54.28%;H, 10.58%; P, 12.97%.

Found:

Example 5 Tetraethyl tridecylidene diphosphonate is hydrolyzed to the acid refluxing about 454 grams with about 600 ml. of concentrated HCl for about 2 to 3 hours. Evaporation to dryness yields the acid, tridecylidene diphosphonic acid, C H CH[PO(OH) which is analyzed with the following results:

Calculated: C, 45.34%; H, 8.78%;P, 17.99%. Found: C, 44.86%; H, 8.71%; P, 17.90%.

Example 6 Tri-ammonium tridecylidene diphosphonate,

is prepared by dissolving about 334 grams of the free acid obtained as in Example 5 in about 1 /2 liters of 10% NH OH solution and evaporating the aqueous solution to dryness at about 120 C. with the anhydrous form of the salt being formed.

Example 7 2 5)2( 3) 4 9)2]2 Example 8 Dicalcium cyclohexyl methylene diphosphonate,

C H CH[PO(OCaO)] J is prepared by dissolving about 322 grams of the free acid (cyclohexyl methylene diphosphonic acid), prepared generally by procedures used in Example 2, in about 1 liter of 20% Ca(OH) solution and evaporating the aqueous solu tion to dryness at about 120 C. with the anhydrous form of the salt being formed.

Example 9 Tetraethyl benzyl methylene diphosphonate prepared generally by the procedures used in Example 1, is hydrolyzed to the acid by refluxing about 347 grams of the ester with about 800 ml. of concentrated HCl for about 4 hours. Evaporation to dryness yields the acid, benzyl methylene diphosphonic acid,

C H CH[PO(OH) 2 Example 10 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 479 grams tetraphenyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about 233 grams of 2-bromobiphenyl is added slowly to the reaction mixture. To ensure a satisfactory degree of reaction the mixture is heated at about 100 C. for about 8 hours. After filtering the potassium bromide, the reaction product is distilled yielding the ester, tetraphenyl biphenyl methylene diphosphonate,

C H .C H CH[ e elzlz Example 1] Tetraethyl dodecylbenzyl methylene diphosphonate, (C12H25 CGH4CH OC2H5 2] 2, prepared generally by' procedures used in Example 1, is hydrolyzed to the acid by refluxing about 425 grams of the ester with about 800 m1. of concentrated HCl for about 4 hours. rEvaporation to dryness yields the acid, dodecyl'benzyl methylene diphosphonic acid, (C12HZ5)CGH4CH 12.

Example 12 Tetraethyl acetophenone methylene diphosphonate CH C(O)C H -CH[PO(OC H prepare-d generally by procedures used in Example 1, is hydrolyzed to the acid by refluxing about 405 grams of the ester with about 800 ml. of concentrated MCl for about 3 hours. *Evaporation to dryness yields the acid, acetophenone methylene diphosphonic acid, CH C(O)C H -CH[PO(OH) Example 13 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 28 8 grams of tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about 333 grams of octadecylbromide is added slowly to the reaction mixture. To ensure a satisfactory degree reaction the mixture is heated at about 120 C. to 140 C. for about 10 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester, tetraethyl nonadecylidene diphosphonat'e,

-Elemental analysis of the product gives the following result:

Calculated: C, 60.5%; H, 11.73%. Found: C, 63.07%; H, 11.49%.

Nuclear magnetic resonance analysis gives a P shift in p.p.m. of 23.9.

Example 14 Into a suitable reaction vessel about 39.1 grams of potassium metal is added slowly to about 288 grams of tetraethyl methylene diphosphonate in about 2.5 liters of xylene. The temperature of the reaction vessel is maintained at about 70 C. After all of the potassium is used up about grams of (x-ClllOlOPYlIOl is added slowly to the reaction mixture. To ensure a satisfactory degree reaction the mixture is heated at about C. to about C. for about 6 hours. After filtering the potassium bromide the reaction product is distilled yielding the ester, tetraethyl pyrryl-l-methylene diphosphonate,

Other methylene diphosphonate esters which can be reacted with metallic sources to form the metallo-ester derivatives, such as the potassio-ester derivatives, according to the procedures as illustrated by the foregoing examples include the following esters: tetramethyl methyl ene diphosphonate, tetra-n-hexyl methylene diphosphonate, tetra-isopropyl methylene diphosphonate, tetradodecyl methylene diphosphonate, tetra-hexadecyl methylene diphosphonate, tetra-toluyl methylene diphosphonate, tetra-xylyl methylene diphosphonate, and the like, as well as mixed esters, such as, diethyl-dibutyl methylene diphosphonate, diethyl-di-n-hexyl methylene diphosphonate, dimethyl-diethyl methylene diphosphonate and the like.

Other halide compounds which can be reacted with the metallo-ester derivatives, such as the potassio-ester derivatives, according to procedures as illustrated by the foregoing example to form compounds of the instant invention include aliphatic hydrocarbyl halide compounds, such as, 3-chloro-2-methyl butene-l; 3-chloro-2-methyl butene-Z; -2-chloro-2+methyl pentane; 3chlor-o-2,2-dimethyl butane; 4-chloro-2, Z-dimethyl butane; 3-chloro- 2,2,3-trimethyl butane; 3-chlorohexane; n-hexyl chloride; n-undecyl chloride; n-hexadecyl chloride; n-hexyl bromide; n-octyl bromide; n-dodecyl bromide; n-tetradecyl bromide; l-bromo-n-caproic acid; 2-bromo hexanoic acid and the like.

Alicyclic halide compounds include cyclopentyl bromide, cyclohexyl chloride, cycloheptanyl chloride, cycloheptanyl bromide, cyclopentadiene dibromide, cyclohexane carboxylic acid chloride, 1-chloro-1-methyl cyclohexane, 3-bromo-cyclohexene, 3-chloro-cyclohexene, 2- chloro-cyclopentadiene, 2-bromo-cycloheptanone, 1-2-dibromo cycloheptane, 1bromo-4tert-butyl-cyclohexane, 1- chloro-l-met-hyl cyclohexane, 1-2-dibromo cycloheptane, 1-chloro-3 methyl cyclohexane, and the like.

Aryl halide compounds include the mono-cyclic arylhalide compounds, such as ch lorobenzene, 2-chloroaniline, 2-amino-4, 6-dichloro phenyl br-omobenzene, 4-bromo aniline and the like, as well as the polycyclic aryl halide compounds, such as, 3-chlo-robiphenyl, 4-amino-4-chloro biphenyl, 2-chloro-1-naphthal, 2-chloro-anthraquinone, 1- chl oro-naphthalene, l-bromo-naphthalene, 2 bromo biphenyl, and the like.

Alkaryl halide compounds include benzyl chloride, {3- phenyl ethyl chloride, 4-methyl benzyl chloride, 3-rnethyl benzyl chloride, Z-methyl benzyl chloride, 2-chlorobenzyl chloride, 4-chlorobenzyl chloride, 3-chlorobenzyl chloride, 4-isopropy1 benzyl chloride, m-xylene dichloride, a-chl-oro acetophenone, benzyl chloroformate, benzyl bromide, B-phenyl ethyl bromide, Z-bromo benzyl bromide, 3-nitro benzyl bromide and the like.

Aralkyl halide compounds include 2-chlorotoluene, 3- chlorotoluene, 4-chlorotoluene, l-chloro-Z-ethyl benzene, 2-ch loro-2-vinyl benzene, 1-chloro-2-isopropyl benzene, 2-chloro-4-isop1'opyl-l-methyl benzene, p-chloro benzoic acid, 2-chloro-4-octyl phenol, 2-chloro-4-nonyl phenol, 2-chloro-4-dodecy1 phenol, 2-benzyl-4-chlorophenol, 2- bromotoluene, 1-bromo-4-ethyl benzene, 4-bromoacetanilide, 4-bromoacetophenone, phenaryl bromide, 4- bromobenzoic acid and the like.

Heterocyclic halide compounds include N-chlorosuccinimide, N-bromo succinimide, 2-chloropyridine, 2- chloroquinaline, 2bromo-5- nitro furan, 2-bromo-5-methyl furan, S-bromo indole, 5-bromo-2-methyl indole, 4-bromo-2-picoline, 3-chloropyridine, 4-chloropyridine, 3-bro- D mo-thiophene, 2-bromo-3,4-dinitro thiophene, 2-chloro thiophene, 2-bromofuran, 3,4-dichloro-tetrahydrofuran, 3,4-dichloro-2,S-diphenyl furan, S-bromoindole, 4chloroindole, 7-chloro-2,3-dimethyl indole, 2-chloro-1,4,6-trimethyl indole and the like.

Other bases or salts of volatile acids which can be reacted with the free acids to produce salt compounds of the instant invention according to the procedures as illustrated by the foregoing examples include the inorganic alkali metal, alkaline earth metal and aluminum salts, oxides and hydroxides, such as, NaCl, NaNO Na O, Na CO KOH, K 0, KCl, K CO KNO LiOH, LiCl, LlNO3, Ll2CO CSOH, CsCl, CSNO3, CS2CO3, CaCl CaO, CaCO MgCl MgO, MgCO BaCO BaCl Ba(OH) Ba(NO SrCA SrCl Sr(OH) Al(OH A1 Al(NO and amines, such as, ethyl amine, diethylamine, propyl amine, propylene diamine, diethylene triamine, hexyl amine, 2-ethylhexyl amine and the like.

Quite unexpectedly organo-methylene diphosphonic acids or the salts thereof were found to exhibit not only good deflocculating or dispersing properties and sequestration properties but also good surfactancy properties. It is highly unusual for all of these properties to be effectively exhibited by the same compound. As can be appreciated, such compounds can advantageously be utilized in applications which can use the foregoing properties, such as, detergent compositions. In many detergent applications such as textile cleaning including synthetic textiles and hard surface cleaning, the ability of the detergent composition to remove the soil, keep the soil suspended in the washing medium, as well as, exerting a water softening effect in the washing medium by sequestration of calcium and magnesium ions, is a parawherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl radicals containing from 5 to 20 carbon atoms and Z is a cation selected from the group consisting of hydrogen in conventional amounts such as is normally used with detergent compositions and which is generally about 5% concentration or below.

Compounds illustrative of the invention were tested for surfactancy properties by determining surface tension measurements with a du Nuoy Tensiometer in distilled water at room temperature. The compounds tested were at concentrations believed representative of detergent concentrations used in actual applications. The results of the test are tabulated below.

illustrative of the invention, i.e. (2) and (3), exhibit the ability to lower the surface tension of water (4). Compounds (2) and (3) compared very favorably with sodium dodecylbenzene sulfonate (5), a widely used surfactant, when used in molar concentrations of 5X10- and 10' It should be noted that compound (1) exhibited no appreciable surfactancy ability since a compound exhibiting a surface tension above about at molar concentrations of 5 10 and 10- is not usually regarded as. a surfactant. As can be appreciated, therefore, by reason of their surfactancy, compounds of this invention are particularly well suited for use in detergent compositions.

Compounds illustrative of the invention were tested for deflocculating properties in a carefully controlled kaolin slurry. The kaolin used in the evaluation was essentially free of impurities and was placed in an aqueous slurry with a solids content about 68%. The slurry throughout the evaluation was maintained at a pH of about 7 with NaOH or HCl. The apparent viscosity was determined with a Stormer Viscometer at 300 r.p.m. The results of the tests are tabulated below.

1 Plastic.

As can be observed from the above table, minor amounts of the compounds illustrative of the invention, i.e., (2) and (3) defiocculated a plastic slurry into a flowable slurry. In addition, compounds (2) and (3) compared very favorably with sodium tripolyphosphate (4), a widely used defiocculant, and compound (1) when used in amounts of about .1 and .15% weight based on a dry clay basis.

Compounds illustrative of the invention were tested for sequestration properties. The conditions of the test were to dissolve .25 gm. of the tetrasodium salt of the compound of the instant invention and .25 gm. of

Na C O in 250 ml. of water and adjust the pH to 12 with NaOH. To the solution is added 0.1 M Ca(NO until a cloudy endpoint, i.e., the precipitation of CaC O is achieved. In order to calculate the pounds of calcium sequestered by 100 pounds of material tested, the volume of 0.1 M Ca(NO used, in cc. units, is multiplied by 1.6. The results of the test are tabulated below.

TABLE 3 Lbs. calcium/100 lbs.

Compound: of compound (1)v T etrasodium octylidene diphosphonate C7H15CH[PO(ONH)Z]2 (2) Tetrasodium tridecylidene diphosphonate C H CH[PO(ONa) As can be observed from the above table, compounds illustrative of the instant invention, i.e., (1) and (2) exhibited the ability to sequester calcium, thus indicating their beneficial use in aqueous systems containing such ions.

The esters of organo-methylene diphosphonic acids were found not only to be substantially miscible with water but also highly soluble in organic solvents, such as hydrocarbon solvent, i.e. hexane and pentane, carbon tetra chloride, haloethylene solvents (perchloroethylene), ethers, alcohols, and the like. Also, the esters were found to impart a solubilizing. action to water in water-immiscible solvents, such as many of the previously mentioned solvents. This totally unexpected property renders them highly useful as gasoline de-icer additives and along with their surfactancy properties renders them useful as dry cleaning detergents. As can be appreciated, however, the unique ability to impart a solubilizing action to water in water-immiscible solvents can be utilized in many and varied applications and, therefore, the foregoing mentioned applications are merely indicative of their use.

The esters of higher alkylidene diphosphonic acids are preferred in applications which use the combined surfactancy and/or water solubilizing properties. These compounds are of the following formula:

wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl radicals containing from to carbon atoms and R R R and R are selected from the class consisting of alkyl groups of from 1 to 20 carbon atoms, aryl hydrocarbyl groups and alkaryl groups with the lower alkyl groups being especially preferred.

Because of the complexity of the ternary solubility diagram of the esters of the instant inventionwaterwater-immiscible solvents the following is set-forth for example purposes only.

A solution of 10 cc. of hexane and 5 cc. of the following esters of the higher alkylidene diphosphonic acids dissolves the amounts of water at room temperature indicated in Table 4. The water was added dropwise until permanent cloudiness or phase separation was observed. The tabulated results are presented in the following table.

TABLE 4 Compound: H O added (cc.)

(1) Tetra ethyl octylidene diphosphonate C7H15CH[PO(OC2H5)2]2 .5 (2) Tetra ethyl tridecylidene diphosphonate C H CH[PO(OC H 2.5

It should be noted that the foregoing example solutions exhibited no phase separation at the end of a one week period of standing nor was there a phase separation after the solutions had been centrifuged at 5,000 rpm. for one hour indicating that the water was completely dissolved in the water-immiscible solvent. It should further be noted that tetraethyl methylene diphosphonate,

10 CH [PO(OC H did not impart a solubilizing action to water in a water-immiscible solvent.

As previously mentioned the ester compounds of the instant invention are useful in gasoline as de-icer additives and are preferably used in amounts of from .005 to 5% by weight. An advantageous feature of these deicer additives, by reason of their phosphorus content, is their ability to function either wholly as the primary additive for surface ignition control or in conjunction with other known phosphorus additives for surface ignition control.

As dry cleaning additives the ester compounds of the instant invention can be used as either the primary surfactant or in conjunction with other surfactants. When used as substantially the primary surfactant with many of the common organic solvents, such as, Stoddards solvent and perchloroethylene, amounts within the range of .05% to 10% by weight are usually sufficient with amounts about 2% by weight being preferred.

In addition, the ester compounds of the instant invention may also be used as extractants for metals in an aqueous-organic solvent system.

Although the compounds of the instant invention as well as their uses have been described with a degree of particularity, the invention herein is intended to be limited only by the claims set forth hereinafter.

What is claimed is:

1. A compound having the formula wherein R is selected from the class consisting of aliphatic hydrocarbyl groups of from 7 to 30 carbon atoms and alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and X is selected from the class consisting of cations selected from the group consisting of hydrogen ions, alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions and amine ions, and aliphatic hydrocarbyl, aryl, alkaryl and aralkyl groups of from 1 to 30 carbon atoms.

2. A diphosphonic acid having the formula wherein R is selected from the class consisting of aliphatic hydrocarbyl groups of from 7 to 30 carbon atoms and alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and X is hydrogen.

3. A salt of a diphosphonic acid, said salt having the formula wherein R is selected from the class consisting of aliphatic hydrocarbyl groups of from 7 to 30 carbon atoms and alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and X is selected from the class consisting of alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions, and amine ions. 4. An ester of a diphosphonic acid, said ester having the formula X0 0 R 0 0X \ll 1 ll/ PC-P XO/ r I oX wherein R is selected from the class consisting of aliphatic hydrocarbyl groups of from 7 to 30 carbon atoms and alicyclic, aryl, alkaryl, aralkyl groups of from 5 to 30 carbon atoms and X is selected from the class consisting of aliphatic hydrocarbyl, aryl, alkaryl and aralkyl groups of from 1 to 30 carbon atoms.

5. A diphosphonic compound having the formula ZO H OZ wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl groups containing from 7 to 20 carbon atoms and Z is a cation selected from the group consisting of hydrogen ion, alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions and amine ions.

6. A diphosphonic acid having the formula wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl groups containing from 7 to 20 carbon atoms.

7. A salt of a diphosphonic acid, said salt having the formula ZO\O R 1+1 ZO Z wherein R is selected from the class consisting of saturated and ethylenically unsaturated aliphatic hydrocarbyl groups containing from 7 to 20 carbon atoms and Z is a cation selected from the class consisting of alkali metal cations, alkaline earth metal cations, aluminum cations, ammonium ions, and amine ions.

8. An ester of a diphosphonic acid, said ester having the formula References Cited by the Examiner UNITED STATES PATENTS 2,339,096 1/1944 Morgan 252-171 2,634,288 4/1953 Boyer 26046l 2,651,656 9/1953 Ladd et a1 260461 2,793,945 5/1957 Walker et al. 44---76 2,889,213 6/1959 Larsen 4476 2,904,514 9/1959 Nusslein 252l71 OTHER REFERENCES Kosolapoff, J. Am. Chem. Soc., vol. 75, pp. 1500-1501 3 CHARLES B. PARKER, Primary Examiner.

FRANK M. SIKORA, Examiner.

R. L. RAYMOND, Assistant Examiner. 

1. A COMPOUND HAVING THE FORMULA 